Advancing Native Mass Spectrometry for Probing Protein Equilibria and Dynamics

University Of Washington, Seattle WA

Investigators

Abstract

With support from the Chemical Measurement & Imaging Program in the Division of Chemistry and partial co-funding from the Molecular Biophysics Program in the Division of Molecular and Cellular Biosciences, Professor Bush and his group at the University of Washington are developing new methods to characterize the equilibria and dynamics of proteins and their complexes. State-of-the-art techniques developed in the Bush lab enable new measurements of the interactions and structures of biological molecules in solution. These measurements address unmet needs for the rapid characterization of biological molecules and biological materials, including their assembly, heterogeneity, quality, and similarity. These measurements will help answer important questions about the structure and function of proteins and protein complexes, important for understanding the molecular basis for human diseases and developing therapeutics. Undergraduate and graduate students working in the Bush lab are trained in measurement science, data science, and technical communication, which prepares them for success in a wide variety of careers that increase the economic competitiveness of the United States. There are unmet needs for measurements that probe protein equilibria and dynamics in solution, especially methods that are fast, sensitive, and tolerant of sample heterogeneity. Native ion mobility (IM) mass spectrometry (MS) has many attributes that make it well positioned to fulfill these unmet needs. However, concerns about differences between equilibrium properties determined using solution- and gas-phase measurements reduces the confidence in native IM-MS data and inhibits the broader adoption of these technologies. This research addresses these unmet needs by (1) using, characterizing, and controlling the electrochemically-induced changes to samples concomitant with electrospray ionization; (2) facilitating the broader adoption of negative ion electrospray ionization for native IM-MS; and (3) using variable-temperature electrospray ionization to rapidly characterize thermal profiles and the extent to which protein folding is reversible. This in turn will enable native IM-MS to play a greater role in biophysics and structural biology, which will contribute to new knowledge of biological processes and cures for human disease. Undergraduate student researchers are developing and fabricating low-cost instruments to expand access to chemical measurements and broaden participation in research. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.